Surface Roughness and Pit Formation in the Ultra-Precision Cutting of Triaminotrinitrobenzene-Based Polymer-Bonded Explosives

Abstract

Abstract. In this study, the effects of feed and tool rake angle on surface pit formation and arithmetic mean roughness Sa of a triaminotrinitrobenzene (TATB)-based polymer-bonded explosive (PBX) simulant were systematically investigated through theoretical modeling, ultra-precision cutting experiments, and surface topography measurements. A feed-induced indentation fracture model for TATB particles was developed based on indentation fracture theory and contact mechanics to quantitatively predict the key characteristic parameters of surface pit formation. On this basis, a comprehensive predictive model for the arithmetic mean roughness Sa was established by integrating the surface pit component predicted by the above fracture model with the matrix residual profile component and the component associated with other influencing factors. Ultra-precision cutting experiments were performed using single-crystal diamond tools with different rake angles at feeds ranging from 1 μm/r to 16 μm/r, and surface topographies were measured using white light interferometry. The results indicated that surface pit depth increased monotonically with feed and stabilized at higher feed values, in agreement with theoretical predictions. The tool rake angle primarily influenced Sa by controlling plastic side flow in the matrix, with the −15-deg rake angle tool yielding optimal cutting performance. The predicted Sa values showed good agreement with experimental measurements, with an average relative error of approximately 5.42%, confirming the validity and reliability of the proposed models and providing a theoretical basis for process parameter optimization in the ultra-precision cutting of TATB-based PBX materials.